The present invention relates to a content detecting apparatus preferably used for detecting ink remaining in an ink-jet printer, a container used for the content detecting apparatus and an ink-jet printer in which the container is used as an ink cartridge.
Up to now, there has been a detecting apparatus proposed as a technique for detecting presence and/or absence of ink remaining in a ink cartridge, the detecting apparatus being arranged that a prism having two inclined interfaces for reflecting twice light projected from a light-emitting part to let the projected light reach a light-receiving part be provided on a bottom of the ink cartridge formed from a material of a refractive index almost equal to that of the ink, which is a content, and that the inclined interfaces of the prism function as a reflecting surface to let the projected light reach the light-receiving part when the remaining ink is absent while the inclined interfaces function as a light permeable surfaces to let the projected light not reach the light-receiving part when the remaining ink is present (refer to JP-A-1995-164626, for example).
Such a detecting apparatus, however, has a problem such that it is impossible to make distinction for judgment between a signal at the light-receiving part in the case of absence of a cartridge (a signal indicating no received light) and a signal at the light-receiving part in the case of absence of remaining ink (a signal indicating no received light) since the both signals are same.
In view of the above, there has been a detecting apparatus proposed in which a prism for detecting presence and/or absence of the ink cartridge is provided on the bottom of the cartridge in addition to the above-mentioned prism for detecting remaining ink to relatively move the same light-receiving/emitting parts between the both prisms so that both of the detection of presence and/or absence of remaining ink and the detection of presence and/or absence of a cartridge can be carried out (refer to JP-A-1998-230616, for example).
The detecting apparatus disclosed in Patent Reference 2, however, has a problem that a structure and/or an operation thereof are complicated since a prism for detecting presence and/or absence of a cartridge should be provided separately from a prism for detecting presence and/or absence of remaining ink in addition to a requirement of relative movement of light-receiving/emitting parts between the both prisms.